Order Crocodilia

• largest with regard to length, up to 20 ft
  21-24 species; 2 native, 1 introduced in US

  • American alligator

  • American crocodile

  • Speckled caimen

Crocodilians have a flexible, semi-erect posture. They can walk either in a low, sprawled “belly walk,” or hold their legs more directly underneath them to perform the “high walk.” Most other reptiles can only walk in a sprawled position.

All crocodilians have, like humans, teeth set in bony sockets. But unlike mammals, they replace their teeth throughout life. Crocodiles and gharials (large crocodilians with longer jaws) have salivary glands on their tongue, which are used to remove salt from their bodies. This helps with life in a saltwater environment. Crocodilians are often seen lying with their mouths open, a behavior called gaping. One of its functions is probably to cool them down.

The crocodilian digestive system is highly adapted to their lifestyle. Crocodilians are known to swallow stones, known as gastroliths, which help digest their prey. The crocodilian stomach is divided into two chambers. The first is powerful and muscular. The other stomach is the most acidic digestive system of any animal. It can digest mostly everything from their prey, including bones, feathers, and horns!

All crocodilians are carnivores. They feed on live animals such as birds, small mammals and fish. Crocodilians use several methods of attack when pursuing live prey. One approach is that of the ambush. The crocodilian lies motionless beneath the water's surface with only their nostrils above the water line. This keeps them concealed while they watch for prey that approaches the water's edge. The crocodilian then lunges out of the water, taking their prey by surprise and dragging it from the shoreline into deep water where the prey is killed.

The sex of developing crocodilians is determined by the temperature of the eggs during incubation, when eggs are kept warm before they hatch. This means that the sex of crocodilians is not determined genetically. If the eggs are kept at a cold or a hot temperature, then their offspring may be all male or all female. To get both male and female offspring, the temperature must be kept within a narrow range.

Female crocodilians care for the young after they hatch, providing them with protection until they grow large enough to defend themselves. In many species of crocodilians, the female carries her tiny offspring in her mouth.

crocodiles and allies